/*
 * This file is part of LanternServer, licensed under the MIT License (MIT).
 *
 * Copyright (c) LanternPowered <https://www.lanternpowered.org>
 * Copyright (c) SpongePowered <https://www.spongepowered.org>
 * Copyright (c) contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the Software), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package org.lanternpowered.server.util;

import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.X509EncodedKeySpec;

public final class SecurityHelper {

    private static SecureRandom random = new SecureRandom();

    public static KeyPair generateKeyPair() {
        try {
            final KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA");
            generator.initialize(1024);
            return generator.generateKeyPair();
        } catch (NoSuchAlgorithmException e) {
            throw new IllegalStateException("Unable to generate RSA key pair", e);
        }
    }

    public static byte[] generateVerifyToken() {
        byte[] token = new byte[4];
        random.nextBytes(token);
        return token;
    }

    public static Key generateX509Key(Key base) {
        try {
            final X509EncodedKeySpec encodedKeySpec = new X509EncodedKeySpec(base.getEncoded());
            final KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            return keyFactory.generatePublic(encodedKeySpec);
        } catch (Exception e) {
            throw new IllegalStateException("Unable to generate X509 encoded key", e);
        }
    }

    private SecurityHelper() {
    }
}